tree.c

   1 #include "tree.h"
   2 #include "blob.h"
   3 #include "cache.h"
   4 #include <stdlib.h>
   5
   6 const char *tree_type = "tree";
   7
   8 static int read_one_entry(unsigned char *sha1, const char *base, int baselen, const char *pathname, unsigned mode, int stage)
   9 {
  10         int len = strlen(pathname);
  11         unsigned int size = cache_entry_size(baselen + len);
  12         struct cache_entry *ce = xmalloc(size);
  13
  14         memset(ce, 0, size);
  15
  16         ce->ce_mode = create_ce_mode(mode);
  17         ce->ce_flags = create_ce_flags(baselen + len, stage);
  18         memcpy(ce->name, base, baselen);
  19         memcpy(ce->name + baselen, pathname, len+1);
  20         memcpy(ce->sha1, sha1, 20);
  21         return add_cache_entry(ce, ADD_CACHE_OK_TO_ADD);
  22 }
  23
  24 static int read_tree_recursive(void *buffer, unsigned long size,
  25                                const char *base, int baselen, int stage)
  26 {
  27         while (size) {
  28                 int len = strlen(buffer)+1;
  29                 unsigned char *sha1 = buffer + len;
  30                 char *path = strchr(buffer, ' ')+1;
  31                 unsigned int mode;
  32
  33                 if (size < len + 20 || sscanf(buffer, "%o", &mode) != 1)
  34                         return -1;
  35
  36                 buffer = sha1 + 20;
  37                 size -= len + 20;
  38
  39                 if (S_ISDIR(mode)) {
  40                         int retval;
  41                         int pathlen = strlen(path);
  42                         char *newbase;
  43                         void *eltbuf;
  44                         char elttype[20];
  45                         unsigned long eltsize;
  46
  47                         eltbuf = read_sha1_file(sha1, elttype, &eltsize);
  48                         if (!eltbuf || strcmp(elttype, "tree")) {
  49                                 if (eltbuf) free(eltbuf);
  50                                 return -1;
  51                         }
  52                         newbase = xmalloc(baselen + 1 + pathlen);
  53                         memcpy(newbase, base, baselen);
  54                         memcpy(newbase + baselen, path, pathlen);
  55                         newbase[baselen + pathlen] = '/';
  56                         retval = read_tree_recursive(eltbuf, eltsize,
  57                                                      newbase,
  58                                                      baselen + pathlen + 1, stage);
  59                         free(eltbuf);
  60                         free(newbase);
  61                         if (retval)
  62                                 return -1;
  63                         continue;
  64                 }
  65                 if (read_one_entry(sha1, base, baselen, path, mode, stage) < 0)
  66                         return -1;
  67         }
  68         return 0;
  69 }
  70
  71 int read_tree(void *buffer, unsigned long size, int stage)
  72 {
  73         return read_tree_recursive(buffer, size, "", 0, stage);
  74 }
  75
  76 struct tree *lookup_tree(const unsigned char *sha1)
  77 {
  78         struct object *obj = lookup_object(sha1);
  79         if (!obj) {
  80                 struct tree *ret = xmalloc(sizeof(struct tree));
  81                 memset(ret, 0, sizeof(struct tree));
  82                 created_object(sha1, &ret->object);
  83                 ret->object.type = tree_type;
  84                 return ret;
  85         }
  86         if (!obj->type)
  87                 obj->type = tree_type;
  88         if (obj->type != tree_type) {
  89                 error("Object %s is a %s, not a tree",
  90                       sha1_to_hex(sha1), obj->type);
  91                 return NULL;
  92         }
  93         return (struct tree *) obj;
  94 }
  95
  96 int parse_tree_buffer(struct tree *item, void *buffer, unsigned long size)
  97 {
  98         void *bufptr = buffer;
  99         struct tree_entry_list **list_p;
 100
 101         if (item->object.parsed)
 102                 return 0;
 103         item->object.parsed = 1;
 104         list_p = &item->entries;
 105         while (size) {
 106                 struct object *obj;
 107                 struct tree_entry_list *entry;
 108                 int len = 1+strlen(bufptr);
 109                 unsigned char *file_sha1 = bufptr + len;
 110                 char *path = strchr(bufptr, ' ');
 111                 unsigned int mode;
 112                 if (size < len + 20 || !path ||
 113                     sscanf(bufptr, "%o", &mode) != 1)
 114                         return -1;
 115
 116                 entry = xmalloc(sizeof(struct tree_entry_list));
 117                 entry->name = strdup(path + 1);
 118                 entry->directory = S_ISDIR(mode) != 0;
 119                 entry->executable = (mode & S_IXUSR) != 0;
 120                 entry->symlink = S_ISLNK(mode) != 0;
 121                 entry->mode = mode;
 122                 entry->next = NULL;
 123
 124                 bufptr += len + 20;
 125                 size -= len + 20;
 126
 127                 if (entry->directory) {
 128                         entry->item.tree = lookup_tree(file_sha1);
 129                         obj = &entry->item.tree->object;
 130                 } else {
 131                         entry->item.blob = lookup_blob(file_sha1);
 132                         obj = &entry->item.blob->object;
 133                 }
 134                 if (obj)
 135                         add_ref(&item->object, obj);
 136                 entry->parent = NULL; /* needs to be filled by the user */
 137                 *list_p = entry;
 138                 list_p = &entry->next;
 139         }
 140         return 0;
 141 }
 142
 143 int parse_tree(struct tree *item)
 144 {
 145          char type[20];
 146          void *buffer;
 147          unsigned long size;
 148          int ret;
 149
 150         if (item->object.parsed)
 151                 return 0;
 152         buffer = read_sha1_file(item->object.sha1, type, &size);
 153         if (!buffer)
 154                 return error("Could not read %s",
 155                              sha1_to_hex(item->object.sha1));
 156         if (strcmp(type, tree_type)) {
 157                 free(buffer);
 158                 return error("Object %s not a tree",
 159                              sha1_to_hex(item->object.sha1));
 160         }
 161         ret = parse_tree_buffer(item, buffer, size);
 162         free(buffer);
 163         return ret;
 164 }